The present work is based on the methodological setting of the LADL studies.In order to establish the body subject to analysis, we selected only the fixed phrases N0 ser/estar Prep X. In this way, we have collected 1138 expressions involving estar Prep X, and 534 with ser Prep X. In order to classify these expressions, we have grouped them according to the number and form of their complements.As to the part pertaining to semantics, the alphabetical indices have allowed us to establish that, concerning ser and estar, all the formal schemes exists for both Spanish and french, at least under the form of fixed expressions.As to the part concerning translation, we have attempted to mesure the isomorphisms of the structures in the two languages; this has enabled us to verify the existence of a near-total parallelism between the structures of the phrases in ser and estar Prep X, and in the structures in être Prép X.